This invention relates to trailer coupler alignment devices, and more particularly, to a stationary trailer coupler alignment device of the type employing a load-bearing rotary screw-driven platform for positioning a trailer coupler directly over a tow vehicle ball hitch.
In the field of recreational vehicles, non-motorized travel trailers are generally towed by a separate vehicle. To accommodate the tow vehicle, the travel trailer is generally equipped with a tongue jack located at the tongue or coupler end of the trailer. The tongue jack is employed to raise and lower a coupler device which is located at the forward end of the trailer. Thus, the tongue jack permits the coupler device to be positioned onto and off of a ball hitch device mounted on the rear end of the tow vehicle.
In the past, this task has been accomplished by aligning the ball hitch device of the tow vehicle directly under the coupler device of the travel trailer. This has been generally accomplished by continuously changing the position of the tow vehicle in a trial and error fashion by numerous backing maneuvers until the ball hitch device was located directly beneath the coupler device. The tow vehicle was positioned so that the ball hitch device was sufficiently close to the trailer coupler device so that when the travel trailer was lowered by releasing the tongue jack, the coupler device captured the ball hitch. The main problem is that the coupler device must be closely aligned with the ball hitch device in order to successfully connect the travel trailer to the tow vehicle.
Several methods have been employed in the past in an attempt to solve this alignment problem. One such method included a trailer hitch system having longitudinal hitch ball movement wherein a trailer tow point could be laterally adjusted. The longitudinal hitch ball movement was facilitated by a screw shaft housed in the trailer hitch system and was readily accessible from either side of the trailer hitch. The hitch system was design to accommodate multiple hitch balls and permitted any one of such hitch balls to be selectively centered on a bumper of a towing vehicle. It was possible to interchange hitch balls of diverse sizes while the trailer hitch system was installed on the towing vehicle. Further, the hitch system was adaptable to any type of towing vehicle and an adaptor was available which permitted attachment of other types of hitches which were also laterally adjustable therewith. The screw shaft was mounted within a screw block positioned through a circular threaded portion. The hitch balls were mounted in a ball retaining plate and when the screw was rotated, the screw block traveled along the screw shaft and laterally displaced the hitch balls.
Another attempt to solve the problem included a trailer hitch having a laterally adjustable coupling member. The travel hitch with the adjustable coupling member also included a follower which comprised a sleeve threaded on a screw. A globular coupling element such as a hitch ball was secured to the upper portion of the follower. A crank was provided and when rotated, the follower traveled along the screw and laterally displaced the hitching element for providing the laterally adjustable coupling member.
Yet another method for attempting to solve the alignment problem included a drawbar coupling for use in motorized vehicles such as tractors. A block was provided for being laterally moved along a guide. As a worm screw member was turned by means of a bevel screw, the block was in turn laterally displaced along the guide.
A more current method employed a tractor truck having a pivoting frame extending from the rear and having a hitching ball mounted thereon and laterally shiftable by a hydraulic actuator. The frame was movable up or down along a horizontal axis by a hydraulic actuator for moving the hitching ball up or down. Locking pins were provided for unloading the actuator cylinders during over the road operation.
Finally, a different approach has been known by incorporating a hand cranked, non-traveling screw for repositioning the tongue extending from the towed vehicle to extreme angles. Many other methods and devices have been known, each of which employ a threaded screw member and a ball hitch and each with a means for adjusting the lateral position of the ball hitch. Most of these systems employ apparatus which are connected directly to the tow vehicle for adjusting the position of the ball hitch.
Hence, those concerned with the development and use of &owing systems in the non-motorized recreational vehicle field have long recognized the need for an improved alignment system which eliminates the trial and error aligning process between the non-motorized travel trailer and the tow vehicle, which includes an apparatus for receiving the tongue jack of the travel trailer and which may be employed for aligning in a horizontal or angular pattern the trailer coupler to an otherwise stationary vehicle ball hitch, the construction of such a system being rugged but simple and being operated by a common ratchet or wrench and which widely distributes the mechanical load of the travel trailer over the apparatus to avoid binding. The present invention fulfills all of these needs.